1. Field of the Invention
The present invention relates to a portable, gasoline engine driven table-type masonry saw for cutting concrete blocks, bricks, marble, tile, stone and other objects.
2. Description of the Prior Art
Heretofore, masonry saws have been driven by electric motors which are mounted on a lever arm pivotally connected to a support on which a workpiece is positioned. The lever arm includes a shaft on which a saw blade is rotatably mounted. The shaft of the saw blade is operatively connected by means of belts or other drive connectors to the output shaft of the electric motor. In a conventional masonry saw, the entire lever arm together with the electric motor, the drive connection and the saw blade are pivoted on the support for the workpiece. This arrangement is suitable for an electric motor which may be operated at any disposition. In other words, an electric motor does not have to be maintained in a level state during its operation. An electric motor may be angularly disposed relative to its support without effecting the performance of the electric motor.
A number of disadvantages are encountered by utilizing a masonry saw which is powered by an electric motor. If an individual is working at a site which is not serviced by electricity, it is extremely inconvenient or impossible to operate an electric motor. Further, in utilizing a masonry saw, it is conventional to employ water to "wet-cut" the workpiece. By using an electric motor, it is necessary to provide waterproof safety power switches and other safety features to ensure the safety of the individual operating the masonry saw.
Gasoline-powered masonry saws are disclosed in the prior art. Hirth, U.S. Pat. No. 2,159,699, discloses a concrete cutting device wherein a saw blade 35 is operatively connected by means of the belt drive 31 to a gasoline-powered engine 34. As illustrated in FIG. 2 of Hirth, the support pin is mounted on wheels 26, 26' for supporting the engine 34 and the axis of the saw blade 35. The wheels 26 may be angularly disposed relative to the plane of the support pin. In this manner, the gasoline-powered engine 34 is tilted at an angle with respect to the horizontal. Thus, problems can develop in the operation of the gasoline engine 34 due to the angular disposition of the oil within the crankcase. In other words, the lubrication of the gasoline-powered engine 34 will be adversely effected when the engine is tilted relative to the horizontal.
Griswold et al, U.S. Pat. No. 925,333, discloses a circular stone saw. The saw blade 8 is mounted on a shaft 7 which is operatively connected to a drive shaft 3 by means of a belt drive 11. This device is a relatively large structure which is not portable.
McCain, U.S. Pat. No. 2,308,703, discloses a cutting apparatus for cutting quartz crystal slabs from "mother" crystals. A plurality of circular saw blades 34 are mounted on a shaft 33 which is operatively connected to an electric motor 119. It is important to note that the shaft 33 on which the circular saw blades 34 are disposed is permanently positioned relative to the side walls 26. The shaft 33 may not be tilted relative to the support frame 26.
Konway, U.S. Pat. No. 2,783,789, discloses a power driven circular saw. A gasoline engine 76 is securely mounted on a support frame 36. The support frame 36 is positioned on wheels 21. A saw blade 75 is mounted on a shaft 69 which is operatively connected by a pulley and gear arrangement to the gasoline-powered engine 76. A crank 62 is provided to vertically adjust the saw blade 75 relative to a workpiece.
Wilson, U.S. Pat. No. 2,889,141, discloses a mobile concrete saw device which is operated by a gasoline engine. The gasoline engine 12 is mounted on a frame 10 which is supported on wheels 58. A saw blade 44 is positioned on a shaft 28 which is operatively connected to the gasoline engine 12 by means of belts 54. This device is used to saw concrete slabs on a highway. The device disclosed by Wilson is not a portable, table-type gasoline-powered masonry saw.
Henderson et al, U.S. Pat. No. 3,248,152, discloses a vehicular router having a vertical cylindrical tool. A gasoline-powered engine 5 is positioned on a horizontal support B mounted on wheels W. A cutting tool 60 is operatively connected to a motor 61 which is supplied with current through a line L' extending from the motor though the guide G into the generator unit. Again, the device disclosed by Henderson et al is designed to be operated in a horizontal position and does not include a cutting member designed to be tilted relative to the drive motor.
Simmons, U.S. Pat. No. 3,271,079, discloses a pavement cutter. An engine 114 is positioned on a frame 12. A saw blade 50 is mounted on a bushing 62 which is operatively connected to the engine 114 to impart rotation thereto.
Stoljarov et al, U.S. Pat. No. 3,360,298 discloses a stone cutting machine with a mobile carriage. Electric motors are provided for rotating a plurality of cutter blades 28 and 36. This device is somewhat comparable to a conventional electrically powered masonry saw. In addition, this device is somewhat equivalent to the other prior art patents discussed hereinabove in that it is an extremely large machine which is designed to be operated by an individual seated in the chair 14.